There has been a general increase over time in processor speed and the size of RAM and ROM. The screen size has also gotten bigger, the linkport has changed from just the standard I/O to USB, and there is now a built-in clock. Several of the calculators have since been discontinued by TI, however.

The TI graphing calculator has changed dramatically since Texas Instruments introduced the TI-81 in 1990. The calculator not only boasts several new features and functionality, but has greatly improved in its appearance and its existing features and functionality. In addition, the current series of graphing calculators being produced by Texas Instruments is upgraded from the previous series of graphing calculators, with those calculators no longer being produced but instead being discontinued in favor of the current series.

Over time and based on educational feedback, Texas Instruments has targeted their graphing calculators for specific segments of the school population. In particular, TI has a calculator for middle school (the TI-73), high school and college (the TI-83+/84+), and advanced math and science (the TI-89 Ti/V200). Each of those calculators provides its own specific set of features and functionality, including the TI-73 allowing investigation of number patterns and plotting data in various formats, and the TI-89 Titanium/Voyage 200 featuring a Computer Algebra System (CAS) and interactive 3D/Differential Equation graphing.

The most recent calculator series released by Texas Instruments in 2007 was the TI-Nspire series. The calculators represent a radical departure from any of the previously released graphing calculators by TI, and feature a completely different look and feel. In addition to the different appearance, they also function completely different and utilize a different format for almost everything — the menus and associated commands are different, the built-in programming is different, although it provides a much larger screen and 16-level grayscale. The calculators were very much designed with educators in mind, as they provide many enhancements for educators in the classroom. At the same time, TI has really hindered much of the programming capabilities that were available on their previous calculators, and thus the calculators are not really meant to do any serious programming. However, there are efforts underway by the TI community to try to unlock the calculators and their associated programming protections put in place by Texas Instruments.

An upgrade to the original TI-Nspire series was released in 2011, and it itself was even more radically different than the original TI-Nspire. It not only features a completely new aesthetic look, but also provides many changes in terms of its functioning. The calculator is the first TI calculator to support color, providing a full 16 colors, and it has support for multiple standard image formats (.bmp, .png, .jpg, and .gif).

Of course, the TI-Nspire series is still very much unknown to the TI community, and there is not much information available for people looking to write programs and games for the calculators. The calculators also have placed rigid constraints on the programming capabilities built-in, and so there are efforts underway to attempt to document the calculators and to circumvent the programming protections that TI has put in place to prevent programmer misuse of the calculators.

Graphing technology has changed dramatically since TI first introduced the TI-81 in 1990. Products now boast operating systems that can be electronically upgraded via the Internet, calculator software applications (Apps) for adding specific functionality, and peripherals for data collection and real-world experimentation.

Our educational handhelds have their own microprocessors; their operating systems can be upgraded electronically as new versions are released; and they can be customized with different Handheld Software Applications (Apps) to add functionality for different curricular areas, or general purpose needs.

In the last decade, TI has introduced 11 graphing technology products, many of them improved versions of their predecessors. The current product family includes the most popular graphing product in the United States, the TI-83 Plus, for high school and college math and science; the TI-73 for middle grade students; and the TI-89 and TI-92 Plus for advanced mathematics through college and graduate studies.

Texas Instruments has worked closely with educators and the larger educational community since the inception of the TI-81 in 1990, including involving the educational community in the design of their graphing calculator. They would continue this practice of involving educators in the design and development process with all of their subsequent graphing calculators and related classroom technologies. New calculators have all been created in response to educator needs.

Since the introduction of the TI-81 in 1990, Texas Instruments has continued to release new and improved graphing calculators based on educational feedback. The TI graphing calculator has changed dramatically in both design and functionality in response to educator needs and input. Basically, when TI introduces a new design or functionality change to one calculator, all subsequent calculators also receive that change. Texas Instruments has also tailored each of their graphing calculators to different levels of the educational market with specific features and functionality, including middle school, high school and college, and advanced mathematics through college and graduate studies.

The original TI-81 was actually quite limited in its functioning and capabilities, including lacking a linkport and a backup battery. Both proved to be very detrimental to the success of the calculator, as they essentially handicapped the calculator and prevented people from really doing anything serious with it. The lack of linkport prevented people from sharing and downloading programs, as you could not transfer programs via a link cable but instead needed to manually type code into the calculator. This proved rather cumbersome for most people, and consequently there were limited programs written and released and there never was much of a community developed around it.

The backup battery was important because the calculator (and all TI graphing calculators) stores everything, including programs, variables, and even settings, in volatile memory, and the backup battery is used to avoid the loss of memory when replacing the main batteries. TI quickly realized their mistake, and released an updated version of the TI-81 that utilized the coin-shaped backup battery. All subsequent graphing calculators received a linkport and backup battery.

The TI-Nspire, introduced July 2007, was Texas Instruments' first graphing calculator using non-volatile Flash memory to maintain the information stored in the calculator even with low or empty main batteries.

Over time, TI's newer graphing calculators have each become better equipped with faster processors, more memory, and popular features such as linking capability and flash upgradeability.

Texas Instruments first introduced the computer algebra system (CAS) for symbolic manipulation on its TI-92 graphing calculator released in 1995. It also included a QWERTY keyboard, a faster processor, and more memory.

This also led to the release of other classroom technologies by Texas Instruments, most notably the Calculator-Based Laboratory (CBL) and Calculator-Based Ranger (CBR), which work alongside of the graphing calculator. These devices allow students to run experiments while taking measurements of everyday events, such as temperature, movement, and pressure, and to perform related mathematical analysis on their calculator. They bring to life the process of learning, and help students to see the real-world value of math and science.

Over the years, TI has built unique relationships with teachers to design handheld calculator adaptations that meet the unique needs of both educators and students. The company has developed a line of successful educational solutions, software and related products that have changed the way mathematics is taught. TI's handheld products have made a major impact on business, education and everyday life around the world.

"The majority of our business is now with educational handhelds," said Tom Ferrio, vice president, Educational & Productivity Solutions, TI. "These are generations removed from what most people think of when they say 'calculator.' Our educational handhelds have their own microprocessors; their operating systems can be upgraded electronically as new versions are released; and they can be customized with different Handheld Software Applications (Apps) to add functionality for different curricular areas, or general purpose needs."

TI's business focus is on the use of educational handhelds in learning and teaching. The company provides more educational handhelds to schools and students across the nation than any other educational technology provider. Originally used primarily in math and science, Apps are now making it possible for other subjects to take advantage of the pervasiveness of this tool.

Perhaps the single most significant advance in calculator technology that
has huge ramifications for the future of calculators in mathematics classrooms
has been the invention of “flash ROM.”

What does flash ROM in a calculator do?

Flash ROM is a new type of calculator memory first introduced by Texas Instruments in 1998. Until recently calculators had only two types of distinct memory, ROM and RAM. ROM, or read only memory, can be programmed only once and never changed. All the built-in functionality that comes with a calculator is stored in ROM. ROM is relatively inexpensive, so the amount of ROM used in calculators has increased over the years as more and more functionality has been included. If a calculator had only ROM memory, it would not be possible to enter numbers, store values into variables, or even
graph a given function. For these operations, the calculator needs RAM, or random access memory, which allows new information to be stored.

RAM can be rewritten an unlimited number of times. It is used as scratch space during calculations and also as a place to store information such as equations, lists, programs, and so on. RAM has the drawback that it requires more power to operate than ROM, an important consideration for low-power, battery-operated devices like calculators. Also, RAM has the drawback of being relatively expensive. It is usually the second most expensive part of a calculator, after the display. Despite the drop in prices over the last few years for computer RAM, calculator RAM prices have not dropped as fast because calculators use a different type of RAM. To keep the price of calculators low, the amount of RAM in calculators has been restricted. Flash ROM combines the benefits of both RAM and ROM in that it is ROM but it can be rewritten like RAM,
although it is currently limited to about one hundred thousand rewrites.

Flash ROM supplies much more memory in a calculator. Already, flash calculators can have six to ten times the amount of user memory found on nonflash graphing calculators. Flash ROM allows calculators to be upgraded electronically. A new version of the built-in mathematical software, or base code, can be downloaded to the calculator, replacing the previous version. Students will be able to upgrade their calculators and add the latest features without buying a new calculator. Also, calculator companies will be able to distribute maintenance upgrades that improve the underlying system without replacing the calculator itself. This feature is very important to teachers and parents for economic reasons, since it will make calculator “boxes” last longer.

Perhaps the most significant implication of flash ROM is that it enables calculator software applications, also called flash applications, which will allow the calculators of the future to become small computer platforms for software applications!

What are flash applications?

Flash applications are software programs that run on a calculator. They
can do more than user programs developed in the calculator’s program editor
because they are written in more-powerful software languages (C and
assembly language) that tap into more of the underlying calculator system.
Flash applications can also be faster than user programs for the same reason.
Flash applications provide a way of adding on to the built-in functionality,
or base code, with additional software that is similar in construction. Like
the base code, flash applications are stored in flash ROM and remain there
while running. Therefore, they do not take up valuable RAM space the way
user programs do, they stay on the calculator unless they are deliberately
deleted, and they can’t be accidentally removed by resetting RAM or if the
calculator’s batteries die.

Flash applications can dramatically change the functionality of a calculator,
since they are able to control what is displayed on the calculator screen
down to the level of individual pixels. Flash applications are not limited to
displaying the menus, home screen, tables, and graphs of a standard graphing
calculator but can also display pictures, animations, icons, new types of
menus, and so on. Lessons and activities that used to be delivered as worksheets
or textbook exercises can be illustrated, animated, and electronically
linked to the calculator’s computational features.

For example, Puzzle Tanks (Sunburst Communications1999) is a flash
application for developing mathematical problem-solving skills. Puzzle Tanks
animates the standard problem of obtaining a given quantity of liquid using
tanks of different fixed sizes. It shows the tanks and liquid levels on the calculator display and updates them interactively as the student enters estimates
(fig. 5.3). The game involves four levels of play, each level increasing with difficulty. Notice the remarkable change in the look of the traditional graphing
calculator screen due to the flash application. Anyone familiar with the wide
array of educational software available today can see from this example the educational threshold that calculators are about to cross because of flash
ROM. (For other examples, see www.ti.com/calc/flash/73apps .htm#pt.)

TI-83 Graphing Calculator
The TI-83 is Texas Instruments' response to teacher suggestions for improvements to the TI-82. The TI-83 enhances the many popular features of the TI-82, including the graphing features. In addition, the TI-83 adds advanced statistics capabilities and financial functions. And the keyboard and menus are almost identical to the TI-82 so in the classroom, the TI-83 works seamlessly, side-by-side, with the TI-82.

The TI-83 graphing calculator provides students with over 100 improved capabilities, including advanced statistical abilities such as hypothesis test and confidence intervals, and powerful financial functions such as Time Value of Money (TVM), cash flows and amortization. These additional features allow students to use this one calculator in business, scientific and mathematics classes instead of requiring two separate calculators.

The TI-82 was developed with input from experienced classroom teachers and education leaders, including Franklin Demana of The Ohio State University (Columbus, Ohio). According to Demana, "TI is helping make education reform a reality. TI's approach is to get involved by going into classrooms to find out what teachers need. They work hand in hand with leading educators, listening to the needs of the mathematics community. Then they respond with a product that meets those needs, like the TI-81 back in 1990, the TI-85 in 1992 and now with the TI-82."

TI continued to become more popular, and as a result it decided to improve itself. TI has continually released new models all aiming at refining and improving the basic TI-81 design. Only time will tell what new advances Texas Instruments will give us in the future.

The 1990s have seen the graphing calculator become much more powerful, culminating in 1997 with the TI-92 - virtually a hand-held computer. It should be noted that even as the TI-92 came on the market, Texas Instruments was hard at work developing an improved model. The TI-92 has several features that set it apart from other graphing calculators: symbolic algebra, three-dimensional graphing, and symbolic calculus. In other words, the TI-92 can do any algebra or calculus operation currently taught in mathematics textbooks. It will also graph functions of two variables in three dimensions, a skill that, on a two-dimensional piece of paper, takes quite a bit of insight to accomplish.

In late 1995 Texas Instruments introduced the TI-92, a relatively inexpensive hand-held computer with built-in computer symbolic algebra system (using powerful DeriveTM algorithms) and computer interactive geometry (an almost complete version of Cabri IITM). It was about 2 times the cost of a graphing calculator but probably 25 times more powerful! It was the first of a no doubt new generation of powerful hand-held computers for mathematics education representing the merging of calculators and computers. It is clear to us that inexpensive CAS technology will change the nature of the current style of "computing" in the teaching and learning of mathematics from an almost exclusive paper and pencil symbol manipulation approach to a more balanced approach.

Please notice that this TI-81 from an early manufacturing series lacks a backup battery. The TI-81, like all Texas Instruments graphing calculators including even the latest TI-84 Plus Silver Edition, store the user program, user data and even calculator and display settings in a volatile C-MOS memory. To avoid the lost of the memory while replacing the main batteries, the mentioned calculators use an additional, coin-shaped, backup battery. Please read the warning in the 1st edition of the TI-81 Graphics Calculator Guidebook.

The TI-Nspire, introduced July 2007, was Texas Instruments' first graphing calculator using non-volatile Flash memory to maintain the information stored in the calculator even with low or empty main batteries.

From a technical aspect the TI-81 combines the 8-bit hardware architecture known from the Financial Investment Analyst FIA-10 and the enhanced capabilities from the TI-95 Procalc.

The hardware of the TI-81 is similar to a lot of other products: An 8-bit microprocessor of the Z80 family, a huge ROM of 128k Byte capacity, a RAM of 8k Byte size and a driver for the LCD display. You'll find similar architectures with just another balance of RAM and ROM capacity:

Introduction of Flash Technology

As TI continued to work with educators, they indicated the desire for a way to add more capabilities to the handheld units they've already invested in. At the same time, Flash memory technology, which allows the calculator's software to be upgraded electronically, became affordable. As a result, TI pioneered the use of Flash technology in the educational arena by incorporating it in the graphing units.

In just 13 months, TI developed a line of Flash-based handheld tools and add-on calculator software applications (Apps). In 1998, TI introduced the TI-73 with Flash technology for middle grades, then quickly incorporated the technology into the TI-83 TI-83 Plus and the TI-89 and TI-92 (TI-92 Plus).

Graphing technology has changed dramatically since TI first introduced the TI-81 in 1990. Products now boast operating systems that can be electronically upgraded via the Internet, calculator software applications (Apps) for adding specific functionality, and peripherals for data collection and real-world experimentation.

In the last decade, TI has introduced 11 graphing technology products, many of them improved versions of their predecessors. The current product family includes the most popular graphing product in the United States, the TI-83 Plus, for high school and college math and science; the TI-73 for middle grade students; and the TI-89 and TI-92 Plus for advanced mathematics through college and graduate studies.

TI continued to become more popular, and as a result it decided to improve itself. TI has continually released new models all aiming at refining and improving the basic TI-81 design. Only time will tell what new advances Texas Instruments will give us in the future.

Hand-held graphing computers combine the capabilities of a scientific calculator, a programmable computer, an interactive-graphics computer system, and a limited computer mathematics system that performs symbolic manipulation. These machines are powerful tools for mathematical experimentation and exploration. They are too small to lend themselves to typewriter-style keyboarding, and ultimately this may be the lone distinction that remains between hand-held and micro computers.

Texas Instruments recently announced a family of Flash Technology based calculators (the TI-73 for middle and early high school students, TI-89 for advanced high school and college students, and the TI-92 PLUS module with advanced mathematics software for the existing TI-92s) that will end calculator box obsolesce. Do you remember what we did with our wonderful TI-81s when the “more wonderful” TI-82 was introduced (and then that was followed by the TI-83…)? These new Flash Technology based calculators can be easily renewed with NEW computer software via the internet and also will be able to use software applications from popular sources outside of TI that can be downloaded via the internet. For example, Sunburst Communications is making Some of their more popular software titles available to run on the TI-73. It is important to note that Flash Technology means that calculator functionality can expand as curriculum needs change. We are entering a new era of technology value added!

Prior to 1996 graphing calculators provided only some of the important features of a computer algebra system (CAS) - all but the symbol manipulating software of a CAS - at far less cost and often in a more user friendly environment PC based computer algebra systems. In 1996, a remarkable hand-held “portable and affordable” complete CAS with CABRI computer dynamic geometry was introduced by Texas Instruments (the TI-92). The TI-92 uses the same computer CPU than the early Macintosh computers! Now other powerful hand-held CAS are available as well such as the new TI-89 and Casio CFX-9970.

A computer algebra system (CAS) is a software program that facilitates symbolic mathematics. The core functionality of a CAS is manipulation of mathematical expressions in symbolic form.

The first popular computer algebra systems were muMATH, Reduce, Derive (based on muMATH), and Macsyma; a popular copyleft version of Macsyma called Maxima is actively being maintained. As of today, the most popular commercial systems are Mathematica[1] and Maple, which are commonly used by research mathematicians, scientists, and engineers. Freely available alternatives include Sage (which can act as a front-end to several other free and nonfree CAS).

In 1987 Hewlett-Packard introduced the first hand held calculator CAS with the HP-28 series, and it was possible, for the first time in a calculator, to arrange algebraic expressions, differentiation, limited symbolic integration, Taylor series construction and a solver for algebraic equations.

The Texas Instruments company in 1995 released the TI-92 calculator with an advanced CAS based on the software Derive. This, along with its successors (including the TI-89 series and the newer TI-Nspire CAS released in 2007) featured a reasonably capable and inexpensive hand-held computer algebra system.

CAS-equipped calculators are not permitted on the ACT, the PLAN, and in some classrooms because they may affect the integrity of the test/class,[2] though it may be permitted on all of College Board's calculator-permitted tests, including the SAT, some SAT Subject Tests and the AP Calculus, Chemistry, Physics, and Statistics exams.

The TI-92 series of graphing calculators are a line of calculators produced by Texas Instruments. They include: the TI-92 (1995), the TI-92 Plus (1998,1999), and the Voyage 200 (2002). The design of these relatively large calculators includes a QWERTY keyboard. Because of this keyboard, it was given the status of a "computer" rather than "calculator" by American testing facilities and cannot be used on tests such as the SAT or AP Exams while the similar TI-89 can be. However, for the ACT, the TI-89 cannot be used; the TI-84 can.

The TI-92 was originally released in 1995, and was the first symbolic calculator made by Texas Instruments. It came with a computer algebra system (CAS) based on Derive, and was one of the first calculators to offer 3D graphing. The TI-92 was not allowed on most standardized tests due mostly to its QWERTY keyboard. Its larger size was also rather cumbersome compared to other graphing calculators. In response to these concerns, Texas Instruments introduced the TI-89 which is functionally similar to the original TI-92, but featured Flash ROM and 188 KB RAM, and a smaller design without the QWERTY keyboard. The TI-92 was then replaced by the TI-92 Plus, which was essentially a TI-89 with the larger QWERTY keyboard design of the TI-92. Eventually, TI released the Voyage 200, which is a smaller, lighter version of the TI-92 Plus with a QWERTY keyboard and more Flash ROM. The TI-92 is no longer sold through TI or its dealers, and is very hard to come by in stores.

14.1.5 History of TI graphing calculators

TI's first graphing calculator was the underpowered (by today's standards) TI-81. The next entry was the well-rounded TI-85, which had quite a bit of functionality and IMHO an absolutely marvelous menu system. Presumably, TI started soliciting teachers for their opinion of the TI-85. Apparently the word came back that the TI-85 had too much functionality, things that would not be used by the teachers and which would be potentially confusing to the user. So TI took the TI-85 back to the shop and cleared out many of the truly useful things, including long variable names and imaginary numbers. While they were at it, they did come up with some new things, like the Text() command and the Table function. With the TI-82 that resulted, TI began their marketing effort in earnest, and pretty soon teachers across the nation were using the TI-82 in class and making their students buy them too.

The TI-85 still had a main advantage in some calculus functions that the TI-82 didn't have, but that ended when the TI-92 came out. Since the TI-92 had a CAS, it far outclassed the TI-85 and became as popular with calculus teachers as the TI-82 was with algebra teachers. The TI-85, already a minority due to the lack of marketing effort behind it, now became completely marginalized due to the two-tiered system of the TI-82 and TI-92 which were endorsed for student use by TI and teachers. Given low-end and high-end calculators, there is no place for the middle-end model. Somewhere around this time TI also put out the TI-80, which was very similar to the TI-81 and just as memorable, i.e. not at all.

At this point TI had covered all the levels of mathematics education they needed to and went back to improve what they already had. The big selling TI-82 became the TI-83 along with some new features like graph styles and financial functions. Imaginary numbers went back in too, though it still lacked most of the things that made the TI-85 a far better calculator. The TI-85 itself had enough of a following left from the pre-TI-82 days to warrant its own upgrade to the TI-86, which combined all the TI-85 had to offer with the small amount of nifty new things TI had introduced with the TI-82 and TI-83, along with a sizable memory upgrade. Of course it still couldn't make any headway again the two-tiered system of the TI-83 and TI-92, and TI has been more or less ignoring the TI-85/86 model family ever since, looking back only long enough to stop production on the TI-85.

TI's next big idea was the use of Flash ROM, and the proof of concept took advantage of the expansion slot they'd built into the TI-92 in the form of the Plus Module. It worked fairly well, and they went ahead with the TI-73, an underwhelming middle school (a.k.a. junior high) level calculator, and another version of the big seller, now called the TI-83 Plus. The Flash enabled TI-92 with Plus Module was reworked into the TI-89 for those who where sick of the brick-like TI-92, and a TI-92 Plus proper was also released. Next in line for marginal improvements to the TI-83 model family was the TI-83 Plus Silver Edition, adding a massive amount of Flash ROM archive space, a suite of preloaded Flash Applications, a faster processor, and a black Graph Link cable included in the package. They billed it as being for "power users". This of course ignoring the facts that the true "power users" of the TI user community all own the TI-89 or TI-92 Plus, and that even a power user with a TI-83 series calculator is mostly outclassed by the forgotten TI-86. The follow-up to the 92 Plus will be the Voyage 200, which reduces the case size, adds more Flash ROM, preloaded Flash Applications, and includes a USB Graph Link cable.

The outlook for the near future is the proliferation of Flash Applications for the TI-73, TI-83 Plus [Silver Edition], and TI-89/TI-92 Plus/Voyage 200. Indeed, most of the features that the TI-86 has and the TI-83 doesn't have been turned into Flash Applications for the TI-83 Plus. If you don't mind loading up the Flash ROM space, the TI-83 Plus can have everything it lacks except long variable names. The TI-86's extremely useful polynomial solver and simultaneous equation solver have turned up as Flash Applications for the TI-89/TI-92 Plus as well, although in those cases it's only a cosmetic improvement, as that calculator could already handle such problems from the home screen.

TI has also taken strides in recognizing the existence of calculator games and the significant presence of TI graphing calculator users on the internet. One of the Flash Applications that the TI-83 Plus Silver Edition comes loaded with is Detached Solutions' game collection PuzzPack. TI worked with ticalc.org to make a CD-ROM of popular games from their program archive for inclusion in Graph Link packages, although that ended in disaster. The TI website's revamped student section even includes a games page with featured games and links to several of the best known calculator related websites.

1990 — TI-81 Released

July — TI-81 released by Texas Instruments

1991
1992 — TI-85 Released

April — Graph-TI mailing list started by Professor Bert Waits of The Ohio State University and Texas Instruments in support of educators
July — TI-85 released by Texas Instruments

1993 — TI-82 Released

July — TI-82 released by Texas Instruments

1995 - TI-92 Released
1996 - TI-83 Released

With the famous TI-81 Texas Instruments entered the market of Graphing calculators. Instead of the traditional 1-line display this kind of calculator offers a dot matrix display with 64 * 96 addressable pixels. In the normal calculator mode up to 8 lines of text information are shown. The TI-81 traces back to the Casio fx-7000G, the world's first Graphing calculator.

The main features of the TI-81 in a short summary:
• Graphing of up to 4 functions at one time.
• Parametric graphing to analyze up to three parametric equations.
• Manipulation of three matrices with dimensions of 6*6.
• One- and two-variable statistical analyses with up to 150 data points.
• Up to 37 programs with a total of 2400 bytes.

Please notice that this TI-81 from an early manufacturing series lacks a backup battery. The TI-81, like all Texas Instruments graphing calculators including even the latest TI-84 Plus Silver Edition, store the user program, user data and even calculator and display settings in a volatile C-MOS memory. To avoid the lost of the memory while replacing the main batteries, the mentioned calculators use an additional, coin-shaped, backup battery. Please read the warning in the 1st edition of the TI-81 Graphics Calculator Guidebook.

The TI-Nspire, introduced July 2007, was Texas Instruments' first graphing calculator using non-volatile Flash memory to maintain the information stored in the calculator even with low or empty main batteries.

From a technical aspect the TI-81 combines the 8-bit hardware architecture known from the Financial Investment Analyst FIA-10 and the enhanced capabilities from the TI-95 Procalc.

The hardware of the TI-81 is similar to a lot of other products: An 8-bit microprocessor of the Z80 family, a huge ROM of 128k Byte capacity, a RAM of 8k Byte size and a driver for the LCD display. You'll find similar architectures with just another balance of RAM and ROM capacity:

The TI-83 graphing calculator provides students with over 100 improved capabilities, including advanced statistical abilities such as hypothesis test and confidence intervals, and powerful financial functions such as Time Value of Money (TVM), cash flows and amortization. These additional features allow students to use this one calculator in business, scientific and mathematics classes instead of requiring two separate calculators.

The TI-83 is Texas Instruments' response to teacher suggestions for improvements to the TI-82. The TI-83 enhances the many popular features of the TI-82, including the graphing features. In addition, the TI-83 adds advanced statistics capabilities and financial functions. And the keyboard and menus are almost identical to the TI-82 so in the classroom, the TI-83 works seamlessly, side-by-side, with the TI-82.

The TI-82 was developed with input from experienced classroom teachers and education leaders, including Franklin Demana of The Ohio State University (Columbus, Ohio). According to Demana, "TI is helping make education reform a reality. TI's approach is to get involved by going into classrooms to find out what teachers need. They work hand in hand with leading educators, listening to the needs of the mathematics community. Then they respond with a product that meets those needs, like the TI-81 back in 1990, the TI-85 in 1992 and now with the TI-82."

Fifteen years ago desk top computers and calculators were viewed as quite different. Computers were powerful, expensive, and ran sophisticated software. Calculators were inexpensive and did only elementary numerical computations. Scientific calculators are now very inexpensive ($10 to 20 US) and have significantly changed some of the mathematics curriculum taught in most countries. For many years desktop computers have remained expensive and thus still are not used nearly as widely as they should be in the teaching and learning of mathematics in colleges and universities. Ten years ago calculators took a giant evolutionary step and added new software functionality in ROM found only desktop PC computers. These were the so-called graphing calculators, first invented by Casio in 1985. Graphing calculators started a revolution in the teaching and learning of mathematics in the United States and in many other countries as well. Before graphing calculators, professors had to rely exclusively on expensive computers (usually housed in a separate computer laboratory) to deliver computer enhanced visualization in mathematics teaching and learning. Only a few elite colleges and universities could provide such an experience to all mathematics students on a regular basis. A CAS (computer algebra system), available usually only on expensive PC's, generally consists of three main software packages - symbol manipulating software, numerical solvers, and computer graphers. 1995.

In late 1995 Texas Instruments introduced the TI-92, a relatively inexpensive hand-held computer with built-in computer symbolic algebra system (using powerful DeriveTM algorithms) and computer interactive geometry (an almost complete version of Cabri IITM). It was about 2 times the cost of a graphing calculator but probably 25 times more powerful! It was the first of a no doubt new generation of powerful hand-held computers for mathematics education representing the merging of calculators and computers. It is clear to us that inexpensive CAS technology will change the nature of the current style of "computing" in the teaching and learning of mathematics from an almost exclusive paper and pencil symbol manipulation approach to a more balanced approach.

CAS allows new pedagogical methods. For example, calculus procedure are presented as "white box" procedures where we allow student use of some algebraic, non-calculus, "black box" procedures. The white-box/black box principal was first introduced by Professor Bruno Buchberger from the Research Institute for Symbolic Computation in Linz, Austria. We now need to be more specific and explicit about a controversial issue. We can no longer spend out time in the mathematics classroom doing everything we did in the past paper and pencil era and adding on the many topics and methods our students need for the technological intensive future they face. We have much to learn about our future mathematics curriculum and the details of how we will get there.

Derive Newsletter from the International Derive Users Group
www.austromath.at/dug/dnl01.pdf

About the DERIVE User Group
The DERIVE User Group was founded founded in 1991. The DUG now consists of more than 500 members from all over the world. The DUG publishes the DERIVE-Newsletter four times a year and organizes local User Group meetings.

Each DERIVE-Newsletter has 46 pages minimum (40 pages 1995 and 34 pages before), with information about how DERIVE and the TI-92/89 is being used and useful hints for working with the program and the TI-92/89 and Voyage 200.

Fill in the application form and become a member of the DUG. All back issues of the DERIVE Newsletter may be ordered. Find some highlights of the past on the back of the application form.

DERIVE Newsletter Contributions

The goals of the DERIVE Newsletter are to enable the exchange of experiences with DERIVE and the TI-92/89 as well as to create a group to discuss the possibilities of new methodological and didactic manners in teaching mathematics.

Please send all DERIVE Newsletter contributions to the DUG. Contributions will be edited but not assessed. By submitting articles the author gives her/his consent for reprinting in the DERIVE Newsletter.

muMATH is a computer algebra system, which was developed in the late 1970s and early eighties by Albert D. Rich and David Stoutemyer of the Soft Warehouse in Honolulu, Hawaii. It was implemented in the muSIMP programming language which was built on top of a LISP dialect called muLISP. Platforms supported were CP/M and TRS-DOS (since muMATH-79), Apple II (since muMATH-80) and MS-DOS (in muMATH-83, the last version, which was published by Microsoft).

The Soft Warehouse later developed Derive, another computer algebra system. The company was purchased by Texas Instruments in 1999, and development of Derive ended in 2006.

Derive was a computer algebra system, developed as a successor to muMATH by the Soft Warehouse in Honolulu, Hawaii, now owned by Texas Instruments. Derive was implemented in muLISP, also by Soft Warehouse. The first release was in 1988. It was discontinued on June 29, 2007 in favor of TI-Nspire. The last and final version is Derive 6.1 for MS-Windows.

Since Derive required comparably little memory, it was suitable for use on older and smaller machines. It was available only for Windows and DOS platforms and was used also in TI pocket calculators.

Graphing technology has changed dramatically since TI first introduced the TI-81 in 1990. Products now boast operating systems that can be electronically upgraded via the Internet, calculator software applications (Apps) for adding specific functionality, and peripherals for data collection and real-world experimentation.

"I've used graphing technology in my classroom for five years," said Melissa Rowe, math teacher, South Grand Prairie High School. "The advancements in the tools have helped my students advance deeper into the math and master more complex subject matter than ever before."

In the last decade, TI has introduced 11 graphing technology products, many of them improved versions of their predecessors. The current product family includes the most popular graphing product in the United States, the TI-83 Plus, for high school and college math and science; the TI-73 for middle grade students; and the TI-89 and TI-92 Plus for advanced mathematics through college and graduate studies.

INTRODUCTION

Texas Instruments' graphing calculators are very popular among students in high school, junior high school, and college. This is especially true in the United States, where they are practically the standard for math courses in the higher grades. TI's models range from inexpensive calculators with basic functionality to sophisticated calculators suitable for use throughout college-level math courses and beyond.

Playing a large part in their popularity is the fact that TI's graphing calculators can be programmed in a language closely resembling BASIC and, in many cases, in low-level assembly language. On calculators with link ports, these programs can be copied to other calculators of the same type. Many students learn to program on these calculators and eventually move up to computer programming.

Each available model has a different combination of capabilities, memory capacity, programmability, and price. See below for descriptions of each individual calculator.

CURRENT MODELS

Click on a model's name for a picture and detailed information on that calculator.

» TI-Nspire CX & TI-Nspire CX CAS (2011)
The TI-Nspire CX is the most recent evolutionary step. Almost resembling a smartphone, it is the first TI calculator to sport a backlit, color LCD, as well as featuring a removable Wi-Fi module and a rechargeable lithium-ion battery. RAM and storage memory are increased to 64 MB and 100 MB, respectively. The CX no longer features TI-84 Plus keypad support, but it otherwise maintains the features of the earlier Nspire models.

» TI-Nspire (2007)
The TI-Nspire is a significant departure from previous graphing calculators with its grayscale screen and PDA-like appearance. It uses an ARM processor and features 16 MB of RAM and 20 MB of storage space. With the exception of a TI-84 Plus emulation mode, is not compatible with any of TI's previous calculators. When originally released, it completely lacked programming capability. This was incrementally improved with new OS revisions over the next few years, and currently, development in TI-BASIC, Lua, and ASM/C is possible.

» TI-Nspire CAS (2007)
The TI-Nspire CAS is the brother of the TI-Nspire. It is intended to be TI's new flagship graphing calculator with all of the features of the TI-Nspire plus the inclusion of a Computer Algebra System. Unlike the TI-Nspire, the Nspire CAS does not support the TI-84 Plus keypad and so no backwards compatibility exists with the 84 Plus.

» TI-89 Titanium (2004)
The TI-89 Titanium includes all the built-in functionality and power of the original TI-89. It has an increased amount of Flash ROM which is now equal to that of the Voyage 200 except the TI-89 Titanium is in a traditional handheld design. Along with the Voyage 200, it is TI's most sophisticated calculator, with such features as 3D graphing, upgradable flash ROM, built-in assembly language programming, and a generous amount of user-available memory. It now includes a mini USB port in addition to the standard I/O port.

» TI-84 Plus Silver Edition (2004)
The TI-84 Plus Silver Edition is the successor to the TI-83 Plus Silver Edition. Its new features include a new built-in clock and a new mini USB link port in addition to the standard I/O port. The TI-84 Plus SE was the first calculator made by TI to include their new interchangeable faceplates and a kickstand, both of which add to the overall latest stylistic design from TI.

» TI-84 Plus (2004)
The TI-84 Plus is an upgrade to the TI-83 Plus. It remains completely compatible with the TI-83 Plus. Its features include a new built-in clock, a new mini USB link port in addition to the standard I/O port, added clock speed over the TI-83 Plus and an increase in Flash ROM size. The TI-84 Plus has a newly designed case.

» Voyage 200 PLT (2002)
The Voyage 200 PLT was the most advanced calculator Texas Instruments made prior to the introduction of the TI-Nspire. It keeps all of the qualities of the 92+ while increasing the amount of Flash ROM to 2.7 MB. It also comes in the latest stylistic case from TI.

» TI-83 Plus (1999)
The TI-83 Plus is nearly identical to the TI-83, maintaining backward compatibility but greatly increasing available memory and allowing for flash-upgradable ROM and commercial calculator-based applications. This model is the "base model" of the highly popular 83/84 Plus series.

» TI-73 & TI-73 Explorer (1998)
The TI-73, like the older TI-80, is designed for middle school classes, but features flash-upgradable ROM like the rest of TI's newest calculators. It also improves upon the TI-80 with additional statistics functions and a link port for transferring programs and other data.

DISCONTINUED MODELS

Click on a model's name for a picture and detailed information on that calculator.

» TI-83 Plus Silver Edition (2001)
The TI-83 Plus SE is nearly identical to the TI-83 Plus, maintaining backwards compatibility but greatly increasing available memory. Like the 83 Plus, it allows for flash-upgradable ROM and calculator-based applications. It was the most popular among Texas Instruments Z80 calculators, but TI has now discontinued it in favor of the TI-84 Plus and TI-84 Plus Silver Edition.

» TI-92 Plus (1998, 1999)
The TI-92 Plus was available as both a standalone calculator and a module upgrade to the TI-92. It added additional memory, flash-upgradable ROM, and advanced mathematics software. A TI-92 Plus is functionally almost identical to a TI-89. The Voyage 200 has since replaced the TI-92 Plus, since it offers additional features.

» TI-89 (1998)
The TI-89 sported all of the power of a TI-92 Plus, but in a traditional handheld design. Along with the TI-92 Plus and Voyage 200 it was one of TI's most sophisticated calculators, with such features as 3D graphing, upgradable flash ROM, built-in assembly language programming, and a generous amount of user-available memory. The TI-89 Titanium has since replaced this model.

» TI-86 (1997)
Just as the TI-83 succeeded the TI-82, the TI-86 followed up on the TI-85's advanced functionality while adding a stylish new case, assembly support similar to that of the TI-83, and greater memory capacity, while still maintaining compatibility with TI-85 programs.

» TI-83 (1996)
The TI-83 was released as the successor to the TI-82 and featured a newer, more contoured case design that has since been used on all of TI's newer calculators. The TI-83 features backwards compatibility with TI-82 programs and some newer financial functions, but by far the most notable aspect of this calculator is built-in assembly programming capability supported by TI itself. This advance saved curious programmers the trouble of "hacking" the calculator themselves to achieve this functionality, and marked the beginning of TI's embracement of assembly programming. The TI-83 was a popular programming platform, but has now been replaced by the TI-83 Plus, an updated model.

» TI-92 (1995)
When it was released, the TI-92 was a huge departure from TI's previous graphing calculators. It is held horizontally and has a larger display, computer-style QWERTY keyboard, graphical user interface, 3D graphing features, and a Motorola 68000 processor (previous TI calculators relied on slower Z80 processors). Programmers were anxious to make use of the TI-92 for efficient assembly programming, and a loophole was eventually discovered to make this possible. As a result, many impressive games and programs are now available for the TI-92. Unfortunately the TI-92 is rarely used nowadays, having been replaced by the TI-92 Plus (and later the Voyage 200).

» TI-80 (1995)
The TI-80 was released with Algebra I and middle school students in mind. Like the TI-81, it has no link port and is not intended for serious programming. The TI-80's newer cousin, the TI-73, sports flash upgradability and more memory, and has completely replaced the TI-80 in everyday use.

» TI-82 (1993)
The TI-82 was released as a more user-friendly version of the TI-85, at the sacrifice of many of its advanced features, but with a lower price tag. It was long believed that the TI-82 could not be programmed in assembly, but, as with the TI-85, a loophole was eventually found, making the TI-82 a much more attractive programming platform. The TI-83 Plus and TI-84 Plus have taken the place of the TI-82 as the standard in math and science classrooms and the TI-82 has been discontinued.

» TI-85 (1992)
The TI-85 was designed as a powerful engineering and calculus calculator. It was the first TI calculator to have a link port and assembly programming capability (through an unintentional loophole). It has since been eclipsed by the TI-86, which features TI-85 compatibility along with more advanced features.

» TI-81 (1990)
The TI-81, TI's first graphing calculator, was designed for algebra and precalculus. It has since been replaced by newer models which have faster processors, more memory, and popular features such as linking capability and flash upgradability. The TI-81 drew little in the way of third-party games and other programs, since the code must be typed into the calculator by hand.

CHOOSING WHICH MODEL TO BUY

There's a wide variety of TI graphing calculator models you can choose from — which is right for you? Texas Instruments tends to create calculator models for a target area of students in certain grade levels. See below for an overview of who will benefit the most from each currently offered model.

The TI-73 is intended for middle school students in basic algebra classes. It performs many basic arithmetic and graphing functions. However, we only recommend the TI-73 if price is an absolute concern and the calculator will be used only for elementary mathematics. For slightly more expense, the TI-83 Plus will be a far superior buy.
The TI-83 Plus is intended for most high school students. It has many enhanced features in addition to those of the TI-82 and 83. This calculator makes an excellent first choice for the average student. The TI-84 Plus has more available RAM and a faster processor than the TI-83 Plus.
The TI-84 Plus and TI-84 Plus SE are esentially a TI-83 Plus with a few more features, including a clock, USB port, and additional speed and memory. Designed for high school students, these two calculators are for the users wanting to get as much out of their calculator as possible. If you are looking for a calculator based solely on its math capabilities, the TI-83 Plus will do as much as the TI-84 series will at a cheaper price. However, if you can afford the added cost of the TI-84 series, it will provide a better value than the TI-83 Plus.
The TI-89 and its QWERTY-equipped brother, the Voyage 200 PLT, are among the most advanced Texas Instruments calculators on the market. The Voyage 200 PLT is a TI-92+ in a fancy new case with a much needed increase in available Flash ROM, and is at the top of the line. If you need the utmost mathematical horsepower, pick up any of these.
The TI-89 Titanium offers the same mathematical capabilities as the TI-89, so there is no advantage there. However, there is more available Flash ROM, much more! The regular TI-89 is suggested for gamers because not all of the current programs work on the Titanium, although the situation is improving. However the Titanium has several other features, including a USB port, which makes it much more friendly to the average user. The Titanium is essentially a Voyage 200 PLT but without the QWERTY keyboard. The Titanium has replaced the regular 89 for sale in many stores.
The TI-Nspire and TI-Nspire CX exist as both CAS (Computer Algebra System) and non-CAS models. As of 2011, these models are still quite new and are drastically different from any prior calculators. It remains to be seen how well they are adopted. We recommend that average students stick to the other models above until the long-term success of the TI-Nspire is proven.

With this information at your fingertips, we hope that purchasing a calculator will be easier for you. By knowing background information on every Texas Instruments graphing calculator you can make a more informed decision. It's recommended to read up on the features of the calculator(s) you've got your eye on before purchasing just to make sure you're getting what you need.